Reversing switch



April 24, 1934. w. B. TURNER REVERSING SWITCH Filed June 1, 1933 2 Sheets-Sheet l mmmm' Wilh'am B. Tau 7262 nmmm'c' Sum/wan WA/Knew April 24, 1934. w B, NE 1,956,430

William B. Turner Patented Apr. 24, 1934 REVERSING SWITCH William B. Turner, East Orange, N. J assignor to Walker-Turner Company, Plainfield, N. J a corporation of New York Application June 1, 1933, Serial No. 673,820

Claims.

This invention relates to electric switches and has for an object to provide a switch of simple, compact and inexpensive construction adapted more particularly for use on a split-phase motor 5 to reverse the connection of the starting winding to the main winding and thereby provide the motor with selective shift means for controlling its direction of rotation at starting.

With the above and other objects in view, will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages tained thereby will be readily understood by those skilled the art.

In the accompanying drawings, Fig. is a side elevation of a switch embodying the invention.

29 Fig. 2 is a bottom end view of the switch. Fig. 3 is a section on the line 3, 3, 1 with the switch handle and rotary parts in one extreme position. Fig. l is a similar view with the rotary parts in the other extreme position. Fig. 5 is a section on the line 55, Fig. 3. Fig. 6 is a section on the line 6-6, Fig. 3. Figs. 7 and 8 are elevations of the rotatable core member of the switch. Fig. 9 is a bottom end view of the core member. Fig. 10 is a top end view of the stationary shell member of the switch. Fig. 11 is a bottom end view of the shell member and Fig. 12 is a disassembled. perspective view of the rotatable core member and contact shoes.

According to the preferred embodiment of the invention illustrated, the switch comprises a cylindrical shell 1 of molded insulating material, such as bakelite, formed at one end with an outwardly extending attaching flange 2 and at the opposite end with an inwardly extending bearing flange 3. The shell 1 is also formed in the face of its flanged end with a circular recess 4 which is interrupted at diametrically opposed points by stop-lugs 5, Figs. 5 and 10.

The shell 1 carries two diametrically opposed pairs of contact rivets 6, 6' and 7, 7' the inner rounded heads of which project inwardly from the inner surface of the shell 1. The lower eontacts 6, '7 are disposed in a circumferential zone which is spaced below the circumferential zone of the upper contacts 6', 7, as shown in Fig. 5. Terminal lugs S and 9 are connected to the respective contacts 6 and '7. The shell 1 is formed with outwardly projecting spaced lugs 16, 11 which hold the intermediate terminal lugs 8 and 9 from turning about their respective contact rivets 6 and 7.

The shell further carries a third pair of diametrically opposed contacts 12, 13 the inner rounded ends of which, like the inner ends of the contacts 6, 6 and 7, 7', project inwardly from the inner surface of the shell 1. The contacts 12, 13 are spaced 90 circumferentially of the shell 1 from the plane of the contacts 6, 6 and '7, 7.

Further, the contacts 12, 18 are disposed in a circumferential zone intermediate the circumferential zones of the contacts 6. 7 and 6, 7. The purpose of this spacing will be hereinafter ex plained. Terminal lugs 14, 15 are secured to the respective contacts 12, 13 and lie in appropriate rotation-restraining recesses in lugs 16 projecting from the outer surface of the shell 1. In the present instance the upper contacts 6, T have no wire terminals secured thereto.

Disposed within and coaxially of the shell 1 is the cylindrical core 17 of moulded insulating material formed at one end with an operating handle or knob 18 at the base of which are formed the diametrically opposed segmental stop-lugs 19 received in the circular groove 4 in the shell 1. The outer curved walls 19' of the lugs 19, Fig. 9 have a bearing engagement with the circular wall-portions 4 of the groove Fig. 16 and hold the handle end of the core 17 coaxial with the shell 1. The core 17 is journaled at its lower end in the inwardly extending shell-flange 3 and projects below the latter; being formed in its projecting end with a groove 20 for the spring wire key-ring 21 between which and the flange 3 is interposed a dished spring washer 22.

The circumferential lengths of the segmental stop-lugs 5 and 19 are so chosen that the core may be rotated 90 in the shell between two extreme positions. The stop-lugs 19 are preferably made circumferentially long enough to afford an adequate bearing surface contact between their outer walls 19, Fig. 9, and the walls 4, Fig. 10, of the groove 4 to hold the core steady in the shell.

The core 17 is further formed with the diametrically opposed longitudinally extending ribs 23 and with the pockets 24 for the coil-springs 25 which press outwardly upon the segmental cylindrical sheet-metal contact shoes 26 which are circumferentially long enough to bridge the gaps betweenthe contacts 6, 6, 7, '7' on the one hand and the contacts 12, 13 on the other hand.

It will be observed that the contact shoes 26 are curved wardly at their opposite longitudinal edges to engage the core 17 at the base-portions of the ribs 23 which impart rotary motion to the contact shoes when the core 17 is turned. It will be further observed that the springs 25 are disposed in the central circumferential zone of the single contacts 12, 13 and between the spaced zones of the double contacts 6, 6' and '7, '7'. By virtue of this arrangement a single coil-spring 25 may be used behind each contact shoe 26 which is caused to bear on three contacts arranged at the apices of a triangle with the spring in the center of the triangle. This will be clear by referring to Fig. 1. Furthermore the stops 5 and 19 are so related to the stationary and rotary contacts that each contact shoe 26 is caused to bear at all times upon a respective pair of double contacts 6, 6 and '7, 7 and to alternately engage the contacts 12, 13 of the third pair. In other words, when the core is rotated from one extreme position to the other, the springs 25 cross the plane of the double contacts 6, 6, 7, '7, and tilting of the contact shoes 26 is prevented. It also happens that when the contact shoes leave the single contacts l2, 13 in a turning movement they cannot be forced outwardly by the springs 25 into engagement with the wall of the shell 1 for the reason that the longitudinal edges of the shoes 26 will engage the core 1'7 at the bases of the ribs 23 before the shoes are forced outwardly iar enough to drag upon the shell.

In the use of the switch to control the direction of rotation at the starting of a split-phase alternating current motor, the terminals of the main winding M may be connected with the contacts 6 and '7. The starting winding S and usual centrifugal cut-out C are connected in series to the switch terminals 12, 13. The line terminals L, L from the main winding M may lead through a suitable starting switch (not shown) to the source of current supply.

Having thus set forth the nature of the invention, what I claim herein is:

1. The combination with a hollow cylindrical shell of insulating material having an inwardly extending flange at one end and an outwardly extending flange at the other end formed in its face with a circular recess, of a rotary core of insulating material journaled at one end in said inwardly extending flange and formed with an oper ating knob at its opposite end, said core having at the base of said knob a pair of diametrically opposed segmental lugs received in said circular recess, stationary contacts carried by said shell, and a spring-pressed contact rotatable with said core.

2. The combination with a cylindrical shell of insulating material having two diametrically opposed pairs of stationary contacts projecting inwardly from the inner wall thereof and a third pair of diametrically opposed stationary contacts spaced from said first mentioned pairs of contacts, said third pair of contacts being disposed in a circumferential zone intermediate the circumferential zones of the first mentioned pairs of contacts, of a core of insulating material journaled in said shell, a pair of diametrically opposed segmental cylindrical contact shoes intermediate said core and shell each having a segmental length greater than 90 and adapted to engage one pair of said first mentioned pairs of contacts and one contact of said third pair, and a coil-spring between each contact shoe and said core in the circumferential zone of said third pair of contacts, and stop means between said core and shell limiting the turning movement of said core between extreme positions in which each contact shoe engages the same respective pair of said first mentioned two pairs of stationary contacts but a different one of said third pair of contaots.

3. The combination with a cylindrical shell of insulating material having a plurality of stationary contacts spaced 90 apart on the inner wall thereof, of a rotatable cylindrical core of insulating material journaled in said shell and for med with a pair of outwardly projecting diametrically opposed ribs extending longitudinally thereof, a pair of opposed segmental contact shoes embracing said core intermediate said ribs and engaged by said ribs, and spring means interposed between said contact shoes and core.

4. An electric switch comprising a cylindrical shell of insulating material formed at one end with an outwardly extending flange and at its opposite end with an inwardly extending flange, a rotatable cylindrical core coaxial with said shell and having an operating knob at one end adjacent said outwardly extending flange, the other end of said core projecting through and being journaled in said inwardly extending flange, keying means applied to the projecting end of core, stationary contacts carried by said shell, and rotary spring-pressed contact shoes actuated by said cor and disposed intermediate said core and shell.

5. An electric switch having a cylindrical shell of insulating material with at least three stationary contacts arranged on the inner wall there of at the apices of a triangle, a rotary core of in sulating material journaled in said shell, a movable contact shoe actuated by rotation of said core and adapted in one position of said core to engage all three of said stationary contacts, and a coil spring between said core and movable contact shoe, said spring being positioned within said triangle when said contact shoe is in engagement with said three stationary contacts.

WILLIAM B. TURNER. 

